Garmin GpsMap 396 - Flight Test #2

So I set up my other 2 GPS units in the cockpit and put their external
antennas right next to the Garmin. The Lowrance Airmap 1000 and an old
Apollo 920+ showed 5-9 sats up near the 80%. The Garmin showed 8+ sats
pinned at the top and one or two more at 50%. Immediately after liftoff
the Garmin marched down to zero on all sats and lost its lock. The other
2 units stayed strong. The Lowrance got better reception in flight than
on the ground.

After leveling, the Garmin reacquired a lock. 10 seconds later, WAAS
locked. Hit the transmit button and the Garmin again marched down to
zero on all sats and immediately popped back up when the mic button was
released. The 2 old units never blinked the entire time during transmission.

Take up a SE heading, the Garmin goes to zero on all sats and stays
there until I turn to some other direction. The other 2 units keep a
strong lock.

Tried every possible position in the cabin and the Garmin still blanked
out. The other 2 had different sat bars but never went below 80% with 6+
sats. Unplugged all units from ships power and tried the tests on
batteries. Same result. Flew outside the Mode C veil and shut off the
electrical system. Same results. Tried different power settings and it
did not seem to make any difference

When powered back for landing with the nose pushed over, the Garmin
again went out to lunch. The other 2 remained locked and strong.

Brought the whole box o' stuff back to JA Air center after calling them
to obtain agreement for a swap. They swapped the unit and external
antenna and kept the rest of the accessories for the new unit. Made
sense. They did try to talk me into upgrading the software before
agreeing to a swap. I said I would upgrade AFTER we swapped if the
problem remained. After the swap, I would have confidence it is not one
particular bad unit. So, I am not chasing a gremlin that turns out to be
a defective unit.

I would love to go up tonight and try the new unit, however, the
President found it necessary to bung up not one, but 2 30 MILE TFRs FOR
HIS FREAKIN BIRTHDAY PARTY! FOR 24 HOURS! Lovely.

I never did check the SW level of the old unit. I missed that one bit of
data. I will try the new one and check the SW level. If it performs like
the old one, I will upgrade and try again. If it still does not work
after the upgrade, I'll give Garmin a call before taking the unit back
for a refund.

I really do love the weather data. I am hoping I can find the gremlin
and keep the 396.

Will report back late Friday or Saturday.

Mike